The Hat-trick reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Hat-trick

Time you got around to sponsoring a child
In sports, a hat-trick is associated with achieving something in a group of three.

In soccer and hockey (both field hockey and ice hockey), a hat-trick is when a player scores three goals in a single game.

In cricket, a hat-trick is when a bowler dismisses three batsmen with consecutive deliveries (which may, however, be interrupted by an over bowled from the other end of the pitch). Only wickets attributed to a bowler count, i.e. run outss would not contribute to a hat-trick.

It is generally agreed that the term was originally used in cricket, and was connected with the custom of giving a hat or cap to a bowler who achieved this feat. It may be connected with the concept of giving someone their "cap", i.e. acknowledging them as a regular member of a representative team.

Possibly the most famous soccer hat-trick of all time was by Geoff Hurst when he scored 3 times for England in the 4-2 defeat of West Germany in the Football World Cup Final of 1966.
The BBC commentator on this match, Kenneth Wolstenholme spoke one of the most famous phrases in television history: "They think it's all over..." (Geoff Hurst scores the winning goal) "...it is now."

See also: Gordie Howe hat trick